Signal system.



L. W. MILLER.

SIGNAL SYSTEM.

APPLICATION FILED AUG.23. 1915.

1,278,709. Patented Sept. 10, 1918.

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L. W. MILLER.

SIGNAL SYSTEM.

APPLICATION my: AUG.23, 1915.

l,%78,79. Patented Sept. 10,1918.

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LOUIS W. MILLER, OF ROCHESTER, NEW YORK, ASSIGNOR TO J. BURTON WARREN, OF ROCHESTER, NEW YORK.

SIGNAL SYSTEM.

Application filed August 23, 1915.

To all whom it may concern Be it known that I, LOUIS N. MILLER, of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Signal Systems; and I do hereby declare the following to be a full, clear, and exact descrlption of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the referencenumerals marked thereon.

My present invention relates to electrical signaling or communicating systems, and has for its particular object to provide a s1gnaling system adapted to be used in c1t1es and municipalities and it is designed to overcome, the objections of previous police signaling systems, particularly with regard to preventing collusion between otlicers on patrol duty and employees in the police service, station in the main or receiving office of the signaling system. A further object of my invention is to provide a signaling system whereby officers or roundsmen when performing their usual duties on the beats ascribed to them, may be signaled or summoned, from headquarters or from a precinct station as the occasion demands. A further object of the invention is to provide in a signaling system, means whereby an officer from any one of a number of substations may transmit to headquarters or to a precinct station an emergency call for an ambulance or a patrol wagon and receive forthwith a signal from headquarters indicating that the call has been received and understood. A still further object of the invention is to provide means for accurately recording the exact time when an oflicer reports at the various substations arranged on his beat. To these and other ends the invention consists in certain improvements and combinations of parts all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Figure 1 is a diagrammatic view showing the preferred arrangement of service and the apparatus controlled thereby. constituting one embodiment of my invention, and

Fig. 2 is a similar view illustrating the substation apparatus forming a part of the system.

Specification of Letters Patent.

Patented Sept. 1%, 1918.

Serial No. 46,778.

Similar reference numerals throughout the several views indicate the same parts.

In carrying out my invention I provide as shown in Fig. 1, a central oiiice apparatus which is installed at police headquarters or at a police precinct station, to work in conjunction with the substation apparatus shown in Fig. 2. The apparatus shown in Fig. 1 is duplicated for each of the substations of the system, said substations being located at various points throughout the city. The central station and substation are connected by a pair of conductors 4i and 11 normally constituting in conjunction with certain other wires a closed circuit, the current for Which is furnished by a battery X.

The conductors normally act as a closed telephone circuit, since each substation is provided with a telephone instrument W, while at the central oflice the main line conductors lead directly to the answering jack K on the switchboard, with which the central. operators cord circuit (not shown) will cooperate in the usual manner. A lamp I in the central office is arranged to be lighted when an ofiicer at the substation removes the telephone receiver from the hook thereby indicating to the central oiiice operator that the patrolman at the substation desires to converse withthe central oflice. The apparatus at the substation, including the telephone W and Other devices, which will be hereinafter described, are preferably arranged within a box or inclosure mounted upon a pole or any other suitable form of support. Also mounted upon the support and outside of the box is the signaling apparatus comprising a loud ringing polarized bell U bridged in the main circuit, current for which is preferably furnished by a ringing generator F installed in the central office, and also a visual signal comprising one or more. lamps V mounted on supports and adapted to be illuminated by the current from a lighting generator E in the central station controlled preferably by relays D and P in a manner which will be hereinafter described. The switchboard at the central office provided with a ringing key M for sounding the bell U and a lighting switch G for energizing relay D to attractits armature for the purpose'of cutting in the generator E when it is desired to light the lamp or lamps V. A switch S in the box at the substation is arranged so that when the patrolman opens the door of the box to answer the signal the circuit will be broken thereby releasing the armature of relay D to cut out the generator E and extinguish the light in lamp V. With such apparatus either an audible or visual signal may be displayed at each box or substation as desired, so that a patrolman may be summoned to the substation by the central office through the me dium of either one of these signals. The switchboard is also provided with signals whereby the central office operator may not only determine whether or not each circuit is in perfect operating condition, but may also be advised when an oflicer on the beat responds to a signal, and in the event the lights have been displayed at a number of the substations these may be extinguished when the officer called, answers from one of the station's. The emergency signal devices comprise a continuously opera-ting bell or buzzer T connected across the main line by the relay 0, the relay being energized upon operating the switch Q. Also a lamp I in the central station is arranged to be lighted simultaneously with the operation of the switch by the patrolman. The vibrations in the circuit established by the buzzer will also serve to indicate to the central ofiice operator when he plugs into the ack K, the fact that on this circuit the emergency switch at the substation has been operated and that the burning of the light is not due to an accident such as the crossing of cir cuits, or a broken wire or through any trouble on the line, or by the removal of the telephone receiver from the hook at the substation. In. this way the central oflice operator' will be able to accurately determine from whichisubstation the call was received so as to obviate dispatching a patrol wagon to the wrong substation. Likewise the continuous ringing of the buzzer T at the substationv willindicate to the patrolman that the line is in perfect working condition for displaying the proper emergency signal in the central oflice.

In police signaling systems it is desirable to keep an accurate record of the time the officers make their reports at the various substationsv on their beats, so that each and every call transmitted may be recorded, preferably on a time driven ruled record sheet, or chart, and in carrying out this idea I have provided one or more recording relaysC adapted to be energized by closing a local circuit or circuits through the relay when either-of the switches Q, or R are operated for momentarily opening the main line circuit. An armature N carrying a punch or perforater adapted to cooperate with the time driven record sheet is actuated by the relay C when its coil is energized through the closing of the circuit on which the relay the circuit established by the buzzer or howler will cause a howl or whistle in the telephone receiver or receivers at the central oflice and the substations on the line of the beat traversed by the particular patrolman wanted when he pushes the recording button R, thus indicating to the patrolman that the central office desires to get in communication with him and to the central oflice operator that the patrolman is at the substation.

The operation of the recording button or switch R is similar to that of switch Q; except that the high resistance coil P is short circuited through the telephone receiver in the substation instead of through the relay 0. A main line relay A comprises two coils A and A of equal resistance preferably wound upon a single core.

A relay B also comprises two coils wound upon a single core, the resistance of the coils being equal though considerably higher than that of the coils of relay A. Coil B of relay B is arranged in series with the main line and coil B is a local winding normally in open circuit and capable of being energized to complete certain circuits for purposes which will presently be described, the energizing of the coil being brought about by attracting the armatures of the relays A and B through the opening and closing of the switches Q and R to cut out the resistance P of the main line circuit. The main line current traverses the following circuit: beginning at battery X, wire 1, coil B of relay B, contacts B B coil A of relay A, wire 2, contacts D D wire 3, contacts M M wire 4, wire 5, contacts It, R wire 6, contacts P P wire 7 (also wire 8 and switch S when door of sub station box is closed) coil P, wire 9, contacts Q Qj, wire 10, wire 11, contacts M l wire 12, contacts D D wire 13, coil A of relay A, and wire 14 back to bat tery.

The recording relay C as previously stated is arranged in a local circuit and is adapted to be energized when the armature of relay B is defe'nergized upon the opening ofthe main line circuit. The relay C comprises a coil C wound upon a core, one ,end of the coil being connected. to one side of the battery and the other to contact B of relay B. The

armature N on the recording relay C is adapted, when the relay is energized, to be attracted for the purpose of perforating the paper dial or chart on the recording clock N adjacent the relay. The arrangement of the recording clock and the chart I, to be perforated may be varied according to the number of stations or the conditions of service on the line, the principal object being to provide means for accurately recording the exact time when an officer reports at the various boxes or substations arranged on his beat, there being as will be understood, a recording relay for each of the substations.

In despatching the emergency or wa 'on call from the substation to the central 0 ce as previously stated, the switch Q is operated, thereby breaking connection between contacts Q and Q and opening main line circuit thus releasing the armature of relay B, breaking contacts B and B and making contact at B and B*, B and B B and B lVhen connection is made between contacts B and B coils A,- and A of relay A are again connected with the battery when the switch Q is pushed over and connection made between contacts Q, and Q at which time high resistance relay P is short circuited through relay 0, thus causing an abnormal flow of current through the main line relay A, attracting its armature, breaking connection between contacts A and A and making connection between contacts A and A, A and A and A and A When connection is made between contacts A and A current will flow from battery through wires 1, 17 and 27, contacts A and A wire 26, coil B of relay B and wire 25 back to battery. Coil B of relay B being thus energized the armature of the relay will again be attracted and connection broken between contacts B and B thereby deenergizing re-.

cording relay C and making connection between contacts B and B and restoring the main line circuit through coil B of relay B. The armature of relay A still being attracted by the abnormal flow of current through the main line, current for lighting the signal lamp I in the central station will flow from battery through wire 1, coil B of relay B, contacts B and B wires 23 and 29,, contacts A and A, wire 16, contacts A and A*, wire 54, contacts K and K wire lamp I and wires 56 and 20 to battery. At the time the emergency call is despatched by means of the switch Q, the relay 0 having a coil 0 wound upon a core is adapted to be connected across the main line, with the operation of the switch to connect the contacts Q and Q}. When this is done relay 0 becomes energized, current flowing through main conductor A, wire 5, contacts R and R wires 6 and 30, coil 0, wire 31, contacts Q and Q and wire 10 to main line conductor 11. Should connection be broken between contacts Q and Q relay 0 will continue to be energized, until the battery is cut oil at the switchboard by pressing the ringing key M. When connection is broken between contacts Q and Q the current from battery X passing through main line conductor l will continue through wire 5, contacts R and R wires 6 and 30, coil 0 of relay 0, wire 32, contacts 0 and 0 wires 28 and 10 to main line conductor 11. At the same time current for the buzzer T passing through main line conductor 4: will flow through wire 5, wire 29, buzzer T, wire 33, contacts 0 and O and wires 28 and 10 to main line conductor 11. The buzzer will continue in operation until the ringing key M in the central office is depressed by the central oflice operator.

As previously stated the switchboard at the central office is provided with the ringing key M for the purpose of sounding the polarized bell U at the substation as a signal to the patrolman making his rounds that the central otfice wishes to communicate with him. The ordinary main line current furnished by the battery X and normally passing through the switch M will not cause the polarized bell U to be sounded and therefore a means for ringing the bell I have provided the ringing generator F, as previously stated, which is preferably an alternating current generator. The coils of the polarized bell U are connected to the conductors 4 and 11 by wires 33 and 34: and in one of these wires is inserted a condenser U for preventing the flow of the main line current through this branch circuit. lVhen the central otfice operator desires to signal a patrolman on the line by ringing the bell U at the substation he operates the switch M to make connection between contacts M and L1 and M and M, thereby connecting the main line conductors 4 and 11 with wires 35 and 36 leading to the generator F from which the necessary current is received for sounding the bell. At the same time when ringing key M is depressed connection is made between contacts M and M thus completing circuit from battery through wire 37, contacts M and M wire 38, local coil B of relay B, through wire 25 back to battery thereby holding armature of relay B attracted while connection is broken between contacts M and M and l t and M As soon as the oflicer has answered the bell at the substation the ringing generator F is cut out and the main line is thereby automatically restored to normal.

As previously stated a lighting generator E is located in the central station for the purpose of furnishing current with which to light the lamp or lamps V in the substation. The generator circuit is controlled by the switch G and relay D in the central oflice and the high resistance relay P in the sub station, the armature of which is not attracted by the current from battery X normally passing through the main line and the relay. When the central ofiice operator desires, by the use of the lamps V, to signal a patrolman on the line making the rounds of the substations on his beat he signals the substations nearest the last from which the officer reported in the direction in which the oflicer is traveling. This is done by closing the switch G in the central oflice, thus making connection between contacts B and G thereby causing current from battery to flow through wires 1, 17 and 27, contacts A and A", wires 40and 41, contacts G and G wire 42, coil D of relay D and wire 39 back to battery. In this way local coil D of relay D is energized thereby attracting the armature of relay D, breaking connection between contacts D and D and D and D and making connection between contacts D and D D and D and D D and D, which as will be understood cuts out the main line circuit through coils A and A of relay A and coil B of relay B. At the same time coil B is energized to hold the armature of relay B attracted, current flowing from battery through wires 37 and 43, contacts D and D wires 44 and 38, coil B of relay B and wire 25 back to battery. Circuit is also completed from battery through wires 37 and 43, contacts D", D and D wires 45 and 19, red lamp J and wire 20 back to battery. When connection is made between contacts D and D and D and D the lighting circuit is then established from one pole of generator E through wire 46, coil D of relay D, wire 47, contacts D and D wire 12, contacts M andM wires 11 and 10, contacts Q and Q wire 9, coil P, wire 8, contacts S and S of switch S, wires 48 and 6, contacts R and R wires 5 and 4, contacts M and M wire 3, contacts D and D wire 49, ammeter H and wire 50 back to generator E. As long as the red lamp J remains lighted the central office operator will know that the signal lamp at the substation is burning and that the generator circuit in which the lamp is placed is in working condition.

l/Vhen the telephone receiver is off the hook in the substation and armature of relay A is attracted, switch G cannot be operated to cut in generator E. As stated before, the battery current flowing through main line to relay P is not sufficient to attract the armature of the relay, due to the high resistance of the coil P but when a current of a higher voltage from the generator E is passed through the relay in the manner just described, its armature will be attracted, thus making connection between contacts P and P and completing circuit through wire 8, wire 51, lamp V, wire 52, contacts P and P wire 53 and back to wire 9, thereby lighting the lamp V as a signal to the patrolman wanted by the'central office. As soon as the patrolman opens the door of the box at the substation to respond to the call or signal from the central office, connection between contacts S and S is broken thereby opening the main circuit, whereupon the armature o1"- relay D is released and connection broken between contacts D and D and D and I), thus cutting out the generator circuit, which cannot be restored except by closing the switch G. At the same time the main line circuit is restored through contacts D and D of relay D and relays A and B.

A description of the arrangement of the parts of the recording relay C has been given in connection with the operation of the emergency switch Q and as the arrangement is thc'same in the case of the operation of the recording switch B, it will only be necessary (O outline the circuit necessary to com plete the transmission of current through the recording relay when the switch R is operated. 1 11c principal difference in the op eration of the switch Q and the recording switch R is that in the case of the former the high resistance relay P is short circuited through the relay 0, while in the case of the latter the high resistance'relay is short circuited through the telephone receiver Z in the substation. hen the patrolman operates the switch R'to-p'roduce upon the record sheet of the recording clock a record of the time of his report at the'substation, the main line circuit is opened, thereby releasing the armature of relay B" and making connection between cont-acts B and B, B and B and B and B.

The armature of relay B being released and connection made between contacts B and B the recording relay C will be ener gized, current passing from battery through wires 1, 17, contacts B and B", wires 2-3 and 22, contacts A and A, wire 16,con'tacts A and A wire 15, contacts B and B and coil C of relay C and back to battery. hen the armature of: relay B falls away connection is also made between contacts B and B thereby again connecting coil A of relay A with the battery so that when the switch R is pushed over and connection is made between contacts R and R and R and R high resistance relay P is short circuited through wires 57' and 58, receiver Z, wires 59 and 60, contacts R and 3*, wire 5 and back to main line, thus causing an abnormal flow of current through main line relay A, attracting its armature breaking connection between A and A and making connection between contacts A and A A and A and A and A When connection is made be tween contacts A and A current will flow from battery through wires 1, l7 and 27, contacts A and A wire 26, coil B of relay B and wire 25 back to battery. Coil B of relay B being thus energized, the armature of the relay will again be at tracted and connection broken between contacts B and 13", thereby deenergizing relay C and making connection between contacts B and B and restoring the main line circuit through coil B of relay B. The armature of relay A still remaining attracted by the abnormal flow of current through the main line, current for lightina the signal lamp I in the central ofiice will flow from battery through wire 1, coil B of relay B, contacts B and B, wires 23 and 22, contacts A and A, wire 16, contacts A and A, wire 54c, contacts K and K wire 55, lamp I and wires 56 and 20 back to battery. As soon as the push button R is released connection is again made between contacts A and A and the main line is consequently restored to normal.

In cases where patrolmen at the substation wish to get in touch with the central office, communication may be had, as previously stated, through the telephone set W which comprises the transmitter W and the receiver Z on the hook Y and contacts Y and Y and Y and Y for making connection with the main line circuit when the receiver is removed from its hook. When the receiver is removed current will travel through main line wire 4:, wire 5, switch R, wires 6, 30 and 61, contacts Y and Y transmitter W, wire 58, receiver Z, wire 59, contacts Y and Y wires 62 and 9, switch Q and wire 10 to main line wire 11. hen connection is made between contacts Y and Y and Y and Y high resistance relay P is thereby short circuited, thus causing an abnormal flow of current through the main line circuit, attracting the armature of relay A and making connection be tween contacts A and A A and A, and A and A Current then flows from battery through wires 1 and 17, contacts B and 13, wires 23 and 22, contacts A and A wire 16, contacts A and A wire 54, contacts K and K, wire 55, lamp I and wires 56 and 20 back to battery, the lighting of the lamp I being a signal to the central o'lfice operator that a patrolman on the line wishes to talk with the central oiiice. When connection is made between contact A and A coil B of relay B is short circuited through coil B thereby energizing relay B and holding its armature attracted. As soon as the receiver Z is placed on the hook Y in'the substation connection is broken between contacts Y and Y and Y and Y thus restoring the main line circuit to normal, causing relay A to release its armature to allow connection to again be made between contacts A and A".

As stated above, it oftenbecomes necessary for the operator or an oflicer in the central station to talk with a patrolman on the line at one of the substations and to communicate to the patrolman a signal indicating that it is desired to have him get in telephonic communication with the central oilice. The buzzer or howler L which has been provided in the central otlice for this purpose comprises a normally 0 en switch L having contact members 2 and L connected by wires 63, and 641: arranged to connect with branch wires 65 and 66 which lead to the contacts K and K and also main line wires 13 and 2. Contact members L and L are connected to wires 67 and 68 respectively, which connect through condensers 69 and 7 0 with the secondary winding 71 of an induction coil, the primary winding of which is indicated at 7 2. A battery S is provided for energizing the primary winding, one end of which is connected with the contact member L and the other end to a vibrator T in the normally open circuit of the battery S. One side of the battery is connected with the contact L by the wire 7 4 and the other side to the vibrator by the wire 75. Whenever the central oflice desires to notify the patrolman making the rounds on his beat that he is ranted on the telephone, the switch L of the buzzer or howler L is closed, thereby connecting the howler with the main line through the engagement of contacts L and L L and L and L and L The switch is allowed to remain closed until the patrolman reaches one of the substations on his beat and operates the switch R to record, at the central oflice, the time of his report at said station. As soon as he operates the switch R the high resistance relay P is short circuited through the telephone receiver Z thereby causing an abnormal flow of current through the main line, thus causing the buzzer L to produce a howl or whistle in the receiver at the substation, which will notify the patrolman that he is wanted on the phone by the central office. The removal of the telephone receiver by the patrolman will cause the lamp I to be lighted in the central oflice, which will indicate to the central ofiice operator that the patrolman is on the line. As soon as the central otfice operator plugs into the jack K the whistle will also be audible in the central oliice telephone receiver and will indicate to the operator that the patrolman at the substaaion is on the phone in answer to the signal produced by the buzzer L. The switch L of the buzzer is then opened and the whistle in the telephone receiver is thereby discontinued.

In the event that there are a number of the lamps V on the substation circuit controlled by the generator E, the ammeter H, serving to show the amount of current passing through the circuit, will indicate to the central ofiice operator whetheror not any of the lamps in the circuit have become eX- tinguished. The central ofiice signal lamp I, which is preferably arranged to furnish a white light, may be tested from time to time by plugging into the jack switch K. When this is done connection is made between contacts K and K current then flowing from battery through wires 1, 17 and 27, contacts A and A, wires 40 and 73, contacts K and K wire 55, lamp I and wires 56 and 20 back to battery.

While I have preferably described my signaling system as being operated by the use of a direct current it will be seen that the apparatus may also readily be used in connection with an alternating current.

I claim as my invention:

1. In a signal system, the combination with a central station, a substation and a normally closed line circuit connecting them, a resistance in the line circuit, an emergency signal at the central station, an electromagnet in the main circuit normally maintaining the signal in an inoperative condition and adapted to be operated by short circuiting the resistance, a line relay, a recording mechanism, a relay for controlling the same provided with a circuit adapted to be closed by the line relay when the main circuit is opened, and opened by the line relay when the resistance is short circuited, a normally open branch circuit connected to the line at the substation and a switch for opening the main circuit and closing the branch circuit to short circuit the resistance.

2. In a signal system, the combination with a central station, a substation and a normally closed line circuit connecting them, a resistance in the line circuit, an emergency signal at the central station, an electromagnet' in the main circuit normally maintaining the signal in an inoperative condition and adapted to be actuated for operating the same by short circuiting the resistance, a normally open branch circuit connected to the line, a switch in the main circuit at the substation adapted when operated to open the main circuit and to short circuit the resistance by closing the branch circuit, a recording mechanism, a relay in a normally open circuit for controlling the same, a second relay adapted upon the operation of the switch opening the main circuit to cause said first mentioned relayto be energized and upon short circuiting the resistance to cause the relay to be denergized.

3,. In a signal system, the combination with a central station, a substation and a normally closed line circuit connecting them, an emergency signal at the central station, an electromagnet in the line circuit having an armature normally maintaining the emergency signal in an inoperative condition,"a doublewound relay having one of its coils normally in the main circuit, arranged to be deenergized upon the opening of the main circuit, and the other coil in an open circuit and arranged to be energized upon the attraction of said armature, a recording mechanism, a relay controlling it having a circuit adapted to be closed between the period of deenergization of the first mentioned relay coil and the energization of the second mentioned relay coil, a resistance in the main circuit and a switch in the substation adapted when operated to open the main circuit and to short circuit the resistance the opening of thecircuitcausing the deenergization of the first mentioned relay coil and the short circuiting of the resistance causing the electromagnet to attract said armature for the purpose of operating the emergency signal and energizing said second mentioned relay coil.

4. In a signal system, the combination with a central station, a substation and a normally closed line circuit connecting them, an emergency signal at the central station, an electromagnet in the line circuit having an armature normally maintaining the emergency signal in an inoperative condition, a double wound relay having one of its coils normally in the main circuit, arranged to be .denergized upon the opening of the main circuit, and the other coil in an open circuit and arranged to be energized upon the attraction of said armature, a recording mechanism, a relay controlling it having a circuit adapted to be closed between the period of deenergization of the first mentioned relay coil and the energiza tion of the second mentioned relay coil, a normally open branch circuit connected to the line at the substation and provided with a sounder, a resistance in the main circuit, and a switch at the substation adapted when operated to open the main circuit and to short circuit the resistance by closing said branch circuit, the short circuiting of the resistance causing the electromagnet to at tract said armature for the purpose of operating the emergency signal.

5.'In a signal system, the combination with a central station, a substation and a closed line circuit connecting them, a normally inoperative signal at the substation, of a source of energy at the central station, mechanism at the substation adapted upon connection of the source of energy with the line circuit to operate said signal, a double wound line controlling relay at the central station having one of its coils in the line circuit and the other normally in an open branch circuit, a switch at the central station and means controlled by the switch for closing the branch circuit and connecting the source of energy with the line circuit.

6. In a signal system, the combination with a central station, a substation and a closed line circuit connecting them, a normally inoperative signal at the substation, a source of energy at the central station, of mechanism at the substation adapted upon connection of the source of energy with the line circuit to operate said signal, line controlling mechanism at the central station having an open circuit, a switch at the central station and means controlled by the switch for closing the open circuit and arranged to connect the source of energy with the line circuit.

7. In a signal system, the combination with a central station, a substation and a closed line circuit connecting them, a normally inoperative signal at the substation, a source of energy at the central station, of mechanism at the substation adapted upon connection of the source of energy with the line circuit to operate said signal, line controlling mechanism at the central station having an open circuit, a switch at the central station, means controlled by the switch for closing the open circuit and connecting the source of energy with the line circuit and means at the substation for disconnecting the source of energy and causing the line controlling mechanism to restore the line circuit to normal.

8. In a signal system, the combination with a central station, a substation and a normally closed line circuit connecting them, a resistance in the line circuit, an emergency signal at the central station, an electromagnet in the line circuit normally maintaining the emergency signal in an inoperative condition and capable of being operated to actuate the signal, a double wound relay having one of its coils normally in the main circuit,-arranged to be deenergized upon the opening of the main circuit, and the other coil in an open circuit and arranged to be energized upon the operation of the electromagnet, a recording mechanism, a relay controlling it having a circuit adapted to be closed only bet-ween the period of deenergization of the first mentioned relay coil and the energization of the second mentioned relay coil, a sounder positioned in an open branch circuit at the substation adapted to operate upon closing the branch circuit to short circuit the resistance and arranged to be rendered inoperable only from the central station, and a switch at the substation adapted to open the main and close the branch circuit to short circuit the resistance for the purpose of causing the operation of the electromagnet.

9. In a signal system, the combination with a central station, a substation and a normally closed line circuit connecting them, a resistance in the line circuit, an emergency signal at the central station, an electromagnet in the line circuit normally maintaining the signal in an inoperative condition and adapted to be operated by short circuiting the resistance, a line relay, a recording mechanism, a relay for controlling the same provided with a circuit adapted to be closed by the line relay when the resistance is short circuited, a normally open branch circuit connected to the line at the substation, a switch for opening the main circuit and closing the branch circuit to short circuit the resistance and means at the central station for rendering the signal inoperative and restoring the line circuit to normal.

10. In a composite telephone and signal system, the combination with a central station, a substation and a normally closed line circuit connecting them, a resistance in the line circuit, a signal at the central station, mechanism in the line circuit normally maintaining the signal in an inoperative condition and adapted to operate the same upon short circuiting the resistance, a plurality of signaling members at the substation each of which is adapted when operated to open the line circuit and short circuit the resistance, and signal answering mechanism at the central station common to all of said signaling members, one of said members being provided with means for producing through the answering mechanism a signal at the central station when said member is operated.

11. In a composite telephone and signal system, the combination with a central station, a substation and a normally closed line circuit connecting them, a resistance in the line circuit, a signal at the central station, mechanism in the line circuit normally maintaining the signal in an inoperative condition and adapted to operate the same upon short circuiting the resistance, a recording mechanism, a relay for operating it having a normally open branch circuit, means for closing and opening the branch circuit upon the opening and closin of the line circuit, a plurality of signa ing members at the substation each of which is adapted when operated to open and close the line circuit to short circuit the resistance, and signal answering mechanism at the central station common to all of said signaling members, one of said members being provided with means for producing through the answering mechanism a signal at the central station when said member is operated.

12. In a signal system, the combination with a central station, a substation and a closed line circuit connecting them, a normally inoperative signal at the substation, a generator normally in open circuit, a magnet at the substation adapted upon connection of the generator with the line circuit to operate said signal, a relay at the central station normally in the line circuit, an open branch circuit leading from the line circuit to the relay means for simultaneously causing the relay to open the line circuit to connect the generator therewith and to close the branch circuit through the relay, and a signal at the central station in the branch circuit adapted to be operated upon connection of the generator and line circuit and to be rendered inoperative upon opening the generator circuit, said signal being 10 for the purpose of indicating Whether or not the generator circuit is in operating condition.

LOUIS W. MILLER.

Witnesses:

F. JERDOM, J12, HENRY W. HALL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

